Steam generator



May 13, 194i. G. A. REI-1M STEAM GENERATOR Filed Sept. 26, 1939 3 Sheets-Sheet 2 f//f//Q//f//U /////////j//Q GUJTAV A REHM Patented May 13, 1941 UNITE STATES PATEN OFFICE STEAM GENERATOR Application September 26, 1939, Serial No. 296,634

6 Claims.

This invention relates to steam generators, and more particularly to' steam generators of the type having a bank of upright water tubes and a combustion chamber located at one side of the tube bank.

It is one object oi the invention to provide a steam generator so constructed and arranged that the gaseous products of combustion will be substantially uniformly distributed throughout the tube bank.

It is a further object of the invention to provide a steam generator which will have a comparatively large capacity in proportion to the space required for installation.

It is a further object of the invention to provide a steam generator which will be particularly Vadapted for marine use.

It is a further object of the invention to provide a steam generator having a water cooled combustion chamber of advantageous construction combined with a bank of convectionwater tubes in a novel manner to ensure rapid water circulation and effective heat transfer.

With these and other objects in View, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and inv which like reference, numerals indicate like parts,

Fig. l is a vertical section through a steam generator and a partial front elevation of a similar steam generator set in battery therewith, the section being taken on the line I-I of Fig. 2;

Fig. 2 is a section taken on the line 2 2 of Fig. l; and

Fig. 3 is a section taken on the line 3 3 of Fig. l.

The embodiment illustrated comprises a longitudinal steam-and-water drum l0 and a longitudinal water drum II located therebeneath, these drums being connected b-y a bank of upright water tubes I2. At one side of the tube bank I2 there is provided an upright wall I4, and at the other side of the tube bank there is provided a combustion chamber I5 having a front wall I6, a rear wall I8, a side wall I9, and a roof 2U which slopes upwardly from the side wall I9 to the steam-and-water drum` I i). The combustion chamber I5 is separated from the tube bank I2 by a bridge wall 22, the upper edge of this wall being spaced downwardly from the roof 20. The bridge wall 22 is supported and cooled by a row of upright water tubes 23 which l are connected at their ends to the drums Ill and II, these tubes being larger in diameter and spaced apart more widely than the water tubes I2. A suitable fuel is burned in the combustion chamber, and for this purpose there is shown an underfeed Stoker 2-5 of the well-known twin retort side-dumping type, having a feeding mechanism 26 arranged to feed fuel through the front wall I6 to the retorts. The stoker illustrated is somewhat shorter than the combustion chamber I5, and the lower portion of the rear wall I3 is sloped downwardly and forwardly to the rear end of the Stoker.

The side wall I9 is supported and cooled by upright water tubes 28 and 29 arranged in a row, with the tubes 28 alternating with the tubes 29. The lower ends of these water tubes are connected to a longitudinal header 3B which is connected to the lower drum II by means of a group of tubes 32 located behind the stoker and outside of the combustion chamber. The upper portions of the tubes 28 are bent inwardly and slope upwardly to the upper drum I0, forming a support for the roof 25J of the combustion chamber. The upper portions of the tubes 2) are likewise vbent inwardly and slope upwardly to the upper drum Ill, but the sloping portions of these tubes are located aY substantial distance below the roof 23 and serve to support a baille 36. As shown in Fig. 2, this baille extends rearwardly from the front wall I6, and its rear edge is spaced forwardly from the rear wall i8. The inner edge of :this baille 34 is connected to the bridge wall 22 (see Fig. l), and its outer edge is located adjacent the side wall i9 but is preferably slightly spaced therefrom to allow the downward discharge of soot.

The rear wall I8 of the combustion chamber is cooled by means of a row of upright water tubes 36 which are connected at their lower ends to a transverse horizontal header 3l and at their upper ends to a transverse header 33 which slopes upwardly toward the steam-and-water drum Ill. The upper end of the header 38 is connected to the drum lil by means of a large tube or pipe 39. The header 3l is located in the same horizontal plane as the header Sli, and the adjacent ends of these two headers are connected at right angles, as shown in Fig. 3. As shown particularly in Fig. 2, the tubes 35 are bent to follew the downward and forward slope of the.

rear wall I8 to the Stoker 25, and thence extend rearwardly to the lower header 3l.

The combustion gases are compelled to flow upwardly past the rear edge of the baille 34, and to reach the forward portion of the tube bank I2 they must travel forwardly above this baille. Accordingly, these gases tend to take the path of least resistance and to flow directly into the rear portion of the tube bank. In order to counteract this tendency and obtain a. substantially uniform distribution of the gases from front to rear of the tube bank, I provide means to divert a substantial portion of the gases forwardly without preventing the flow of the proper quantity of gases into the rear part of the tube bank. For this purpose there is provided a baille 4I located adjacent the top of the bridgewall 22 and in effect forming an' upward extension of this wall. As shown particularly in Fig. 2, the baflle 4! increases in height toward the rear, so that the gases will be deflected forwardly in the desired manner. It will be noted that the baille 4| Vcooperates with the roof 20 thereabove to provide a gas passage or opening which increases in width toward the front wall IB.

Referring now to Fig. 1, it will be seen that a baille 43 is provided which extends downwardly from the steam-and-water drum Il! and terminates somewhat above the lower drum Il. This baffle serves to deflect the hot gases downwardly after they have passed over the bridgewall 22, the gases then flowing beneath the baille and upwardly between the baille and the side wall I4 to a gas outlet duct 45 provided with the usual damper 46. As shown in Fig. 2, the duct 45 is preferably located near the front end of the setting so that the draft or suction in the duct will aid in bringing about a uniform distribution of the combustion gases throughout the tube bank I2.

Certain of the water tubes I2 are preferably utilized to form an economizer in which the incoming feed water is heated, so that the temperature of the outwardly owing gases may be reduced to a comparatively low value. For this purpose an upright plate 48 is mounted within the steam-and-water drum III between the second and third rows of tubes (counting from the wall I4), and the feed water is delivered by a pipe 49 to the trough thus'formed within the drum. A box I is provided within the lower drum II to enclose the lower ends of the four rows of tubes I2 nearest the wall I4. With this construction the feed water is compelled to flow downwardly through two rows of tubes to the box 5I and thence upwardly through two rows of tubes before it can enter the general circulation of the steam generator.

As indicated by the fragmentary front elevation of a second steam generator at the right hand side of Fig. 1, the novel construction illustrated is particularly adapted for an installation in pairs of opposite hand. In such an arrangement, the flue gases can readily be discharged to a commonstack. In case of a marine installation,rfor which the improved steam generator is well suited, the stack would be located on the longitudinal center line of the ship, and the drums I0 and Il would extend lengthwise of the ship.

The operation of the invention will now be ap- .parent from the above disclosure. Fuel is burned on the stoker 25, and the hot gases flow upwardly from the fuel bed and are deected rearwardly by the baille 34 into a concentrated steam. The gases thereupon flow upwardly between the water tubes 29 and are then compelled by the baille 4I to spread out substantially uniformly lengthwise of the setting as they ow over the top of the bridgewall 22 and into contact with the water tubes I2. In flowing upwardly behind the baffle 34, the gases from all parts of the fuel bed are brought together in such a manner as to cause them to mix and thereby substantially eliminate any stratification which may be present. It will be noted that before passing among the closely spaced tubes I2 the gases must flow twice across the comparatively widely spaced tubes 29 and once across the comparatively widely spaced tubes 23. This construction provides an effective slag screen, and ensures that any fluid slag carried in suspension by the gases will be sumciently cooled before it reaches the tubes I2 to prevent it from adhering thereto and thus blocking the gas passages. In passing among the tubes I2 the gases are reduced to a comparatively low temperature before they are discharged to the duct 45. Feed water is delivered through the pipe 49 and flows downwardly through the two rows of tubes I2 nearest the wall I4 into the box 5I and thence upwardly through the two adjacent rows of tubes I2 to the upper drum I0. Steam will be generated in the tubes 28, 29, 36 and 23, and in the tubes I2 between the wall 22 and the baille 43. The tubes I2 on the other side of the baffle 43 will serve as downcomers. The tubes 32 will supply water from-the lower drum II to the headers 30 and 31, which in turn will supply water to the tubes 28, 29 and I5. Thus an adequate circulation is ensured` My improved steam generator provides a large and effective heat absorbing surface in a comparatively small space. The combustion charnber walls are well supported and cooled by water tubes, and a sufficient length of gas travel is provided to ensure complete combustion before the gases enter the tube bank I2.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums. walls providing a combustion chamber at one side of the tube bank, a bridge wall between the combustion chamber and the tube bank so arranged that hot gases from the combustion chamber must flow over the bridge wall to pass among the water tubes, a baille located in the upper portion of the combustion chamber arranged to deflect the gases rearwardly into a concentrated stream, and a gas outlet duct located on the opposite side of the tube bank from the combustion chamber and near the front portion of the tube bank.

2. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls providing a combustion chamber at one side ofthe tube bank, a bridge wall between the combustion chamber and the tube bank so arranged that hot gases from the combustion chamber must flow over the bridge wall to pass among the water tubes, a baille located in the upper portion of the combustion chamber arranged to deect the gases rearwardly into a concentrated stream, and a baille located adjacent the topof the bridge wall arranged to deflect a portion of the gases forwardly before they pass among the water tubes.

3. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, Walls providing a combustion chamber at one side of the tube bank, means providing an elongated opening through which gases may flow from the upper portion of the combustion chamber into the tube bank, the opening decreasing in width toward the rear, and a baie located in the combustion chamber and arranged to deect the gases rearwardly before they reach said opening.

4. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, Walls providing a combustion chamber at one side of the tube bank, a bridge wall between the combustion chamber and the tube bank so arranged that hot gases from the combustion chamber must flow over the bridge wall to pass among the water tubes, upright water Wall tubes associated with the side wall of the combustion chamber opposite the bridge wall, the upper portions of the Water Wall tubes extending across the combustion chamber in spaced relation to the roof thereof andconnecting with the steam-and-water drum, a baffle supported by the said upper portions of the water wall tubes and arranged to deflect the gases rearwardy into a concentrated stream, and a baffle located adjacent the top of the bridge Wall arranged to deflect a portion of the gases forwardly before they pass among the tubes of the tube bank.

5. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls providing a combustion chamber at one side of the tube bank, a bridge wall between the combustion chamber and the tube bank so arranged that hot gases from the combustion chamber must iow over the bridge wall to pass among the water tubes, up-

right water wall tubes associated with the side wall of the combustion chamber opposite the lbridge wall, the upper portions of the Water wall tubes extending across the combustion chamber and connecting with the steam-andwater drum, the said upper portions of certain of the water wall tubes forming a support for the roof of the combustion chamber, and the said upper portions of the other water wall tubes being spaced downwardly from the roof of the combustion chamber, and a bailie supported by the upper portions of the last mentioned Water wall tubes.

6. A steam generator comprising a longitudinal steam-and-water drum, a longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls providing a combustion chamber at one side of the tube bank, a bridge wall between the combustion chamber and the tube bank so arranged that hot gases from the combustion chamber must flow over the bridge wall to pass among the water tubes, upright water Wall tubes associated with the side wall of the combustion chamber opposite the bridge wall, the upper portions of alternate water wall tubes extending beneath the combustion chamber roof to support the same and connecting with the steam-and-water drum, and the upper portions of the other water Wall tubes extending across the combustion chamber in spaced relation to the roof thereof and connecting with the steam-and-water drum, and a bafe supported by the said upper portions of the last mentioned water wall tubes.

GUSTAV A. REI-IM. 

